When Steve Lavin took over the St. John’s program, the first realization he came to hit him like a sucker punch in the gut: The Red Storm players he inherited had no counterpunch — none.

When they were hitting shots — the equivalent of landing punches — they were a formidable opponent. But when the opponent made a run, the Johnnies covered up in a corner and tried to survive the onslaught.

The players who took the court yesterday for St. John’s — seven freshmen and sophomores — are all Lavin’s recruits. At times they didn’t shoot it well, didn’t handle it well, didn’t defend well, but when the opening game of the season was up for grabs, the Red Storm dropped Detroit with a 16-4 run that turned a 60-53 deficit into a 69-64 lead en route to a 77-74 triumph at Carnesecca Arena.

Lavin’s Johnnies can’t bang in the post and their rebounding left a lot to be desired. But one play during a late dead-ball lull sums up the fight in this team:

When Phil “The Rock” Greene stepped to the line for two free throws with 6.8 seconds left, Detroit’s P.J. Boutte, in a blatant attempt to distract, screamed, ‘‘Box shooter!’’ Freshman Chris Obekpa, who made one of the most spectacular debuts in school history, glared at the Titans guard and stalked him for a few steps.

“We know how to fight,’’ said mercurial guard D’Angelo Harrison. “We had guys that hadn’t played in a game like this. Having them step up and make plays and rebound the ball was amazing. We’re going to grind it out all the way.’’

Instead, the Red Storm gleefully headed to the airport for a flight to Charleston, where they will learn more about themselves with three games in four days in the Charleston Classic. Yesterday, however, they learned plenty, but nothing more important than this:

The will to fight, and fight back — the Johnnies trailed by as much as 10 in the second half — is there.

“The biggest positive was our poise down the stretch,’’ Lavin said. “We showed a good resilient spirit, what I call our response mechanisms were impressive, because they could have easily gone quietly into the night.’’

The player who lit it up was Obekpa, whom we have renamed Oblockpa.

Obekpa, the 6-foot-8 forward from Nigeria — by way of Our Savior New American on Long Island — set a school record with eight blocked shots. He also grabbed 10 rebounds and scored seven points, the last two on an elbow jumper with 1:02 to play.

“Chris Obekpa guarded the rim like I’ve never seen before,’’ said Greene. “It was crazy.’’

Speaking of crazy, Harrison, who did not start but came off the bench to score a game-high 22 points, clearly is the go-to player now that Moe Harkless is in the NBA.

Harrison lost his starting job because of his demonstrative behavior. He was not quite the machine he said he would be, but his two steals during that decisive run were crucial.

“He’s a shot maker and a big shot taker,’’ said Greene.

Which can now be said of Greene as well. He made a convincing opening statement for the team’s most improved player. When the offense was lurching in the first half, he scored 13 of his career-high 20 points. He shot 7-of-12 from the field, including 2-of-2 on 3’s with six assists and six rebounds.

Lavin will not have to search for flaws. The Johnnies gave up 32 points in the paint, 20 on second-chance points. And with two seconds left, Lavin had Obekpa inbound the ball against pressure. His deflected pass was scooped up by Detroit’s Juwan Howard Jr., whose game-tying 3-point attempt was short.

“It’s not going to happen again,’’ said Obekpa.

Perhaps. But at least we know the Johnnies will get off the mat if it does.